Added Waterfall Animation

[ShreyDudie]

Digital Rain - ASCII Waterfall in Python

closes #1687

This Python script creates a falling ASCII stream effect reminiscent of the "Matrix" digital rain. Characters cascade down the terminal screen, creating a mesmerizing waterfall-like display.

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Features

• Falling characters in each column
• Randomized character selection from letters, numbers, and symbols
• Continuous animation with adjustable speed
• Works in most terminal environments
• Can be stopped gracefully with Ctrl+C

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Requirements

• Python 3.x
• Terminal or command line that supports ANSI escape codes

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How It Works

1. Drop Initialization:
   Each column has a "drop" position representing where the next character will appear.

2. Frame Generation:
   For each frame, a character is printed at the current drop position, while other positions remain empty.

3. Drop Movement:
   Drops move downwards each frame. Occasionally, they reset to the top, creating a continuous falling effect.

4. Screen Refresh:
   The screen is redrawn by moving the cursor back to the top-left using ANSI escape codes (\033[H).

5. Randomized Characters:
   Characters are randomly picked from a set of letters, numbers, and symbols.

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Configuration

You can adjust these constants at the top of the script:

WIDTH = 80     # Number of columns
HEIGHT = 24    # Number of rows
SPEED = 0.1    # Delay between frames (seconds)
CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789@#$%^&*()"